Large Diameter Gravity Sewer Rehabilitation

Latest Updates:

Notice: Upcoming Construction Work in Downtown San Anselmo

Prior to the 2017-18 wet weather season the contractor for the LDGS II-2 was unable to complete all of the lining and manhole rehabilitation work required to complete the project. Now that the wet weather season has ended and the sewer levels have returned to their dry weather flow conditions, the contractor will be mobilizing back on site to complete the installation off our 36-inch CIPP liners and the rehabilitation of seventeen sanitary sewer manholes on the 18-inch and 36-inch sanitary sewer trunk lines. The contractor will also be installing lateral seals, often called Top Hats, on the previously rehabilitated portions of the 18-inch trunk line. See below for upcoming work and schedule details:

Top Hats

Start Date: Monday May 21st

Duration: Two Nights

Description: The contractor will set up a largetruck at a manhole and use a remotely controlled device to install a sealbetween the private lateral and the lined pipe. Top hats help prevent groundwater from infiltrating into the sanitary sewer main where the new liner meetsan existing private lateral. The equipment set up will be very similar tothe closed circuit television trucks that are routinely set up to inspectunderground pipes.

Location: Work will take place on the18-inch trunk line that runs from the intersection of Bridge Ave. & SanAnselmo Ave. to Ross Ave. & San Anselmo Ave.

Parking: Two to three spots at each manhole.Will be working at one manhole at a time.

Water Restrictions: None

Manhole Frame & Cover Replacement

Start Date: Monday May 28th

Duration: Two Weeks

Description: The contractor will be replacing theiron frame and cover, the only visible part of the manhole, at over a dozenlocations in Downtown San Anselmo. Many of the older frame and covers in thesanitary sewer system contain open pick holes. These holes are what allowmaintenance personnel to pull up the covers but also allow rain water into themanhole and can allow sewer gases to escape. New frames and covers will havesealed pick holes to reduce infiltration and unpleasant odors.

Time: 7:00 AM to 7:00 PM (Day Work)

Location: Work will take place on the18-inch trunk line that runs from the intersection of Bridge Ave. & SanAnselmo Ave. to Ross Ave. & San Anselmo Ave.

Parking: Two to three spots at each manhole.Will be working at one manhole at a time.